A Brooklyn startup is doing just that. Modern Meadow grows real leather from skin cells harvested from a real live (and unharmed) calf. They use the skin cells to produce collagen. In the normal tanning process the animal hide has to have hair, muscle, and fat removed to get down the collagen connective tissue from which leather is made. This lab actually grows the collagen without all that other stuff that a living animal needs. The lab-grown collagen is free of blemishes and makes perfectly good leather. They can even fine-tune things like thickness and elasticity to suit the needs of the final consumer. Right now, they are concentrating on leather because it's the most lucrative, but they could do muscle tissue for meat just as well.